Bob,
The purple ring should correspond to the purple airport dot on your sectional (I shouldn't have called it "a border for the photo" in my earlier post). You're just zoomed in so far, that's how big the purple dot on your sectional has grown. It's not something "artificial" that's blocking out map detail that you would otherwise be seeing--it actually is the underlying map detail.
For example, here's the transition from "pure sectional" to "sectional with RealView overlaid" for my home field.
Zoom level just before RealView appears:
Zoom in once more to get first RealView image:
If RealView were turned off, all you'd be seeing is that same purple circle from the sectional and its white runways getting bigger and bigger. RealView just replaces the white runways with a photo.
Is your experience different from this?